Operations and Supply Chain Management The Core

LINEAR PROGRAMMING USING THE EXCEL SOLVER appendix A 487
We have placed the profits in cells B5 and C5 ($2 and $4), so the profit is calculated
by the following equation: B4*B5 + C4*C5, which is calculated in cell D5. Solver refers
to this as the Target Cell, and it corresponds to the objective function for a problem.
Step 3: Set Up Resource Usage Our resources are machine centers A, B, and C as
defined in the original problem. We have set up three rows (9, 10, and 11) in our spreadsheet,
one for each resource constraint. For machine center A, 4 hours of processing time
are used for each hockey stick produced (cell B9) and 6 hours for each chess set (cell C9).
For a particular solution, the total amount of the machine center A resource used is calculated
in D9 (B9*B4 + C9*C4). We have indicated in cell E9 that we want this value to
be less than the 120-hour capacity of machine center A, which is entered in F9. Resource
usage for machine centers B and C is set up in the exact same manner in rows 10 and 11.
Step 4: Set Up Solver Go to the Data tab and select the Solver option.
1. Set Objective: is set to the location where the value we want to optimize is
calculated. This is the profit calculated in D5 in our spreadsheet.
2. To: is set to Max since the goal is to maximize profit.
3. By Changing Variable Cells: are the cells that Solver can change to maximize profit.
Cells B4 through C4 are the changing cells in our problem.
4. Subject to the Constraints: corresponds to our machine center capacity. Here, we
click on Add and indicate that the total used for a resource is less than or equal to
the capacity available. A sample for machine center A follows. Click OK after each
constraint is specified.